Traction device for automobiles



Aug. 16, 1938.

R. HODGKINSON TRACTION DEVICE FOR AUTOMOBILES Filed June 8. 1936 3Sheets-Sheet 1 Aug. 16, 1938.

R. HODGKINSON 2,126,961

TRACTION DEVICE FOR AUTOMOBILES Filed June 8. 1936 5 Sheets-Sheet 2 Aug.16, 1938. R. HODGKINSON TRACTION DEVICE FOR AUTOMOBILES Filed June 8.1936 5 Sheets-Sheet 3 0 9 a a mm a 2 w w w m a W v gnl L 6 7M Mn n .f wW /.f..,a w k W Z 3 2 3 M 1 w 9 8 .w 0 MW 11 1| 6 m Wm WM w w/ 1Patented Aug. 16, 1938 UNITED STATES PATENT OFFICE TRACTION DEVICE FORAUTOMOBILES Ralph Hodgkinson, Worcester, Mass. Application June 8, 1936,Serial No. 84,046

20 Claims.

This invention relates to devices for increasing the traction ofautomobiles. It is customary to use detachable cross chains or so-calledmud hooks for such purposes, but the application and removal of suchdevices is laborious and otherwise objectionable.

It is the general object of my invention to provide an improved devicefor increasing traction, which device is to be permanently installed inan automobile and which may be rendered operative or inoperative asdesired.

A further object of my invention is to provide means for positioning allparts of the device clear of the ground when the device is inoperative.My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claims.

Preferred forms of the invention areshown in the drawings, in which Fig.1 is a front elevation, partly in section, of one form of my improvedtraction device;

Fig. 2 is a side elevation thereof, partly in section;

Fig. 3 is a detail sectional view, taken along the line 3-3 in Fig. 2;

Fig. 4 is an enlarged detail element;

Fig. 5 is a side elevation of a cam plate forming part of my invention;

Fig. 6 is a plan view, looking in the direction of the arrow 6 in Fig.5;

Figs. '7 and 8 are detail plan views, partly in section and illustratingthe operation of my in- 35 vention;

Fig. 9 is a side elevation of a plunger carrier;

Fig. 10 is a sectional plan View, taken along the line Ill-I0 in Fig. 9;

Fig. 11 is a partial front elevation showing a modified construction;

Fig. 12 is a side view thereof, looking in the direction of the arrow l2in Fig. 11 and showing certain parts in section; and

Fig. 13 is a plan view, looking in the direction of the arrow [3 in Fig.11.

Referring to the drawings, I have shown a wheel l5 mounted on a housingl6 and secured to a driving shaft I1, all substantially of the usualconstruction. The wheel is provided with a brake drum l8 and supportsthe usual tire l9.

My improved traction device comprises a casing (Figs. 1 and 2) having aflange 2| forming a supporting bearing for the casing on the outside ofthe housing IS. A removable cover view of a plunger plate 22 surroundsthe housing l6 and completes the casing.

A plurality of trunnion blocks 25 are pivotally mounted between thecasing 2|] and the cover plate 22 and provide swivel bearings forsleeves 5 21 which are arranged for angular movement therein. Eachsleeve 21 is provided with a camengaging arm 30 at its inner end andwith a friction arm 3| at its outer end and is also provided with ashoulder 32 which limits inward sliding movement of the sleeve relativeto its trunnion block 25.

A coil spring 33 surrounds each sleeve 2'! and has one end fixed in thecasing 20 and the other end engaging the arm 30, as clearly showninFig. 1. The spring 33 tends to turn the sleeve in a direction to forcethe friction arm 3| against the adjacent surface of the tire l9, and thespring 33 also acts to seat the shoulder 32 firmly against theassociated trunnion block 25.

The cam-engaging arm 30 is normally seated in a recess 35 (Fig. 8) inone of the cam projections 36 on a cam plate 37. The cam plate 31 isslidable axially on the housing l6 but is held from rotation by a key 38(Fig. 1) loosely fitting a keyway 39 in the cam plate 31.

A forked lever 40 is pivotally mounted on a stud 4| extending throughears 42 on the housing l6 and the lower forked ends of the lever extendthrough a central opening 43 in the cover plate 22 and engage the outerface of the cam plate 31.

A coil spring 45 (Figs. 7 and 8) is mounted on the housing l6 andpresses outward against the cam plate 31, tending to move the plate fromits holding position, shown in Fig. 8, to its released position, asshown in Fig. 7.

The plunger carrier (Figs. 9 and 10-) is provided with a bearing portion5| adapted to be mounted on the outer face of the flange 2| of thecasing 20, and is provided with three arms 52 adapted to support studs53 extending between the side walls of the carrier. One of the arms isextended outward and provided with an ofiset lug or projection 55 toengage a stop screw 56 (Fig. 1) adjustably mounted in the casing 20.

A plunger 60 is slidable longitudinally in each sleeve 21 and is slottedat its outer end (as indicated at 6| in Fig. 2 and more clearly in themodified construction of Fig. 12) to receive a traction plate 64 whichmay be secured in the plunger 60 by screws 66.

Each traction plate 64 extends over and partially embraces the tire l9and is provided with a roughened tread portion 61. When in normal 55inoperative position, the traction plates 64 clear the the IQ and arenot engaged thereby.

The lower end of each plunger 60 is preferably square in cross sectionand is provided with an elongated slot 10 having a bearing block Hslidable therein and forced yieldingly toward the inner end of theplunger by a coil spring 12.

Each bearing block ll may be provided with ribs l3 slidable inlongitudinal grooves in the side walls of the slots 70 or may beotherwise held from displacement. Each block ll cooperates with theadjacent end of the associated plunger 60 to form a bearing for one ofthe cross pins 53 in the plunger carrier 56 previously identified.

Having described one form of my invention, the method of operation andadvantages thereof are as follows:

Under normal running conditions a link \Fig. 2) is manually adjustedoutward in the direction of the arrow a, thus forcing the lower ends ofthe forked lever All inward against the cam plate 31 and moving the camplate from the position shown in Fig. '7 to that shown in Fig. 8, inwhich position the cam-engaging arms on the sleeves 2'! will be seatedin the recesses 35 of the cam projections 36 on the cam plate 31.

The friction arms 3! will thus be held clear of the tire 19. The camrecesses are so located angularly that the traction plates 64 will bepositioned as indicated in Figs. 1 and 2, well out of possible contactwith the ground.

The link I5 may be connected to any kind of a shipper handle 16 or otherholding device adapted to hold the parts normally in the position abovedescribed.

If the automobile approaches bad traveling occasioned by snuw, mud, orsand, the holding device it for the link 15 may be released, thusallowing the spring to move the cam plate 31 out of engagement with thecam-engaging arms 30 on the sleeves 21. The springs 33 then act to swingthe friction arms 3| against the tire I9, and the casing 29 and allassociated parts will thereafter rotate with the tire and wheel.

As soon as one of the traction plates engages the ground, it will beforced inward and will exert pressure through its spring 12 and bearingH on the plunger carrier 50, moving the carrier angularly in a directionto draw the two other traction plates 64 inward against the tire.

As each plate 64 engages the ground, it repeats the tightening action ofthe carrier 50, so that the engagement of the traction plates with thetire is substantially continuous.

The traction device will continue to operate as described until theshipper handle or control device 16 is again manually operated to movethe link it in the direction of the arrow 0. in Fig. 2, thus forcing thecam plate 31 inward. When this is done, the cam-engaging arms 39 will beagain caught in the recesses 35 of the cam portions 36, and the devicewill again become inoperative with the traction plates angularlypositioned as shown in Fig. 1.

It will be apparent that the operator has the traction device at alltimes under his immediate control, and that he can throw the device intoand out of operation without leaving his driving position or stoppingthe motion of the car.

V A modified construction is shown in Figs. 11 to 13 in which no partcorresponding to the sleeve 2'! is used. The plungers 80 are sli-dablelongitudinally in trunnion boxes 8i which may be supported between acasing 20 and cover plate 22 as previously described.

The upper end of each plunger is slotted at 82 to receive a tractionplate 83, and a friction arm 84 is clamped or otherwise removablysecured to the upper end of the plunger. A cam-engaging arm 85 issimilarly secured to an intermediate portion of each plunger.

The lower end of each plunger is reduced in size as indicated at 86 andis slidable in a trunnion block 81.

The coil spring 88 is mounted on the reduced portion 86 and acts toforce the plunger longitudinally in the bearing 81 and to cause a nut 89to engage the lower face of the associated trunnion block 81.

Each spring 88 also acts to turn its plunger 80 anti-clockwise, asindicated by the arrow b in Fig. 13, which movement will cause thefriction arm 84 on each plunger to engage the adjacent tire.

The trunnion bearings 31 are mounted in bearing openings in a carrier90, corresponding in function to the carrier previously described. Thismodified construction involves the use of two trunnion bearing blocksfor each plunger but is otherwise somewhat more simple than the construction first described. The use and advantages of the modifiedconstruction is the same as in the first form.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:-

1. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a plurality of spaced outwardly extending plungersmounted in said casing and having traction plates at their outer endsoverlying the tire on said wheel, a friction arm for each plungermovable angularly about the axis of said plunger to engage the tire, asecond arm connected to each friction arm, a device movable to aposition to engage said second arms and to move said friction arms outof engagement with said tire, and manual means to position said device.

2. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a carrier loosely mounted in said casing, a plurality ofspaced outwardly extending plungers having traction plates at theirouter ends overlying the tire on said wheel, a friction arm for eachplunger movable angularly about the axis of said plunger to engage thetire, a second arm connected to each friction arm, a device movable to aposition to engage said second arms and tomove said friction arms out ofengagement with said tire, a spring to move said device in onedirection, and manual means to move said device in the oppositedirection.

3'. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a carrier loosely mounted in said casing, a plurality ofspaced outwardly extending plungers having traction plates at theirouter ends overlying'the tire on said wheel, a friction arm for-eachplunger movable angularly about the axis of said plunger to engage thetire, a cam arm connected to each friction arm, a cam plate mountedconcentric with the wheel and movable to a position to engage said camarms and to move said friction arms out of engagement with saidtire, andmanual means to position said cam plate.

2,126,961- 4. A traction increasing device for an automo-- bile having awheel and tire comprising a casing loosely mounted for rotationconcentric with the wheel axis, a plurality of spaced outwardlyextending plungers mounted in said casing and having traction plates attheir outer ends overlying the tire on said wheel, a friction arm foreach plunger movable angularly about the axis of said plunger to engagethe tire, a cam arm connected to each friction arm, a cam plate mountedconcentric with the wheel and movable to a position to engage said camarms and to move said friction arms out of engagement with said tire, aspring to move said cam plate to said position, and manual means to movesaid cam plate in the opposite direction.

5. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a plurality of spaced outwardly extending plungersmounted in said casing and having traction plates at their outer endsoverlying the tire on said wheel, a friction arm for each plungermovable angularly about the axis of said plunger to engage the tire, acam arm connected to each friction arm, a cam plate movable to aposition to engage said cam arms and to move said friction arms out ofengagement with said tire, and manual means to position said cam plate,said cam plate having cam portions corresponding in number to saidplungers and simultaneously actuating all of said cam arms.

6. The combination in a traction increasing device as set forth in claim5, in which each cam portion has a recess which yieldingly receives oneof said cam arms and thereby circumferentially positions said tractionplates in predetermined positions and out of contact with thetire-supporting surface.

'7. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a carrier loosely mounted in said casing, a plurality ofspaced outwardly extending plungers pivotally connected to said carrierand having traction plates at their outer ends overlying the tire onsaid wheel, a friction arm for each plunger movable angularly about theaxis of said plunger to engage the tire, a cam arm connected to eachfriction arm, a cam plate movable to a position to engage said cam armsand move said friction arms out of engagement with said tire, and manualmeans to move said cam plate axially of said wheel, said cam platehaving cam portions corresponding in number to said plungers andsimultaneously actuating all of said cam arms.

8. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a swiveled bearing block in said casing, a sleeveangularly movable in said bearing block, a plunger longitudinallymovable in said sleeve, a traction plate on said plunger, a tireengagingfriction arm on said sleeve, and manually controlled means to move saidfriction arm into and out of engagement with the tire.

9. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe wheel axis, a swiveled bearing block in said casing, a sleeveangularly movable in said bearing block, a plunger longitudinallymovable in said sleeve, a traction plate on said plunger, a

operative to move said sleeve angularly, and manually operative means toresist said spring and to hold saiddevice normally inoperative.

10. A traction increasing device for an automobile having a wheel andtire comprising a casing loosely mounted for rotation concentric withthe whee-l'axis, a carrier angularly'movable in said casing, adjustablemeans to limit angular movement of said carrier in said casing in onedirection, a plurality of angularly spaced plungers mounted in saidcasing and connected to said carrier, and traction plates on' saidplungers, inward-movement'of any one traction plate causingangular-movement of said carrier relative to said-casing and therebycausing simultaneous inward movement of the other plungers.

11. A tractionincreasing device for an automobile havingajwheel and tirecomprising a casing loosely mounted for rotation concentric with thewheel axis, a carrier angularly movable in said casing, adjustable meansto limit movement of said carrier in one direction, a plurality ofangularly spaced plungers mounted in said casing and connected to saidcarrier, and traction plates on said plun'gers inward movement of anyone traction plate causing angular movement of said carrier relative tosaid casing and thereby causing simultaneous inward movement of theother plungers, the connection between each plunger and said carrierbeing yieldable and permitting further independent movement of anyplunger.

12. In a traction increasing device for an automobile having a wheel andtire, a plurality of angularly spaced traction plates, means to holdsaid plates from rotation with said Wheel and in predetermined angularposition relative to a horizontal plane, means to release said platesfor movement with the associated tire, and means to effect simultaneousmovement of all of said plates directly toward or away from said tire inpaths of travel parallel to the plane of rotation of said wheel.

13. In a traction increasing device for an automobile having a wheel andtire, a traction plate, means to hold said plate normally out ofgroundengaging position and out of contact with the associated tire, afriction member associated with said plate, means to release saidmember, and means to move said member into frictional engagement withsaid tire.

14. In a traction increasing device for an automobile having a wheel andtire, a traction plate, means to hold said plate normally out ofgroundengaging position and out of contact with the associated tire, amember associated with said friction plate and mounted to swing about anaxis approximately radial with respect to said tire, a tire-engagingfriction arm at one end of said member, a second arm on said member, andmanually positioned means to engage said second arm and to thereby swingsaid friction arm to inoperative position.

15. In a traction increasing device for an automobile having a wheel andtire, a traction plate, means to hold said plate normally out ofgroundengaging position and out of contact With the associated tire, amember associated with said friction plate and mounted to swing about anaxis approximately radial with respect to said tire, a tire-engagingfriction arm at one end of said member, a second arm on said member, andmanually positioned means to engage said second arm and to thereby swingsaid friction arm to inoperative position, said latter meanstire-engaging frictionarm' on said sleeve, a spring 3 being alsoeffective to stop and hold said traction plates out of ground-engagingposition.

16. A traction increasing device for an automobile having a wheel andtire, comprising a plurality of angularly spaced traction plates,supports for said plates, means to normally hold each plate yieldinglyin outward inoperative position away from the tire, and connectionsthrough which all of said plates are moved to operative position againstthe tread of the tire by engagement of any one of said plates with thesurface on which the tire is traveling.

17. A traction increasing device for an automobile having a wheel andtire which comprises a plurality of angularly spaced and substantiallyradially movable plungers, traction plates on said plungers, frictiondevices angularly movable about the axes of said plungers to engage saidtire, means to normally hold said friction devices in inoperativeposition, and manual means to release said devices.

18. A traction increasing device for an automobile having a wheel andtire which comprises a casing concentric with said wheel, a plurality ofangularly spaced and substantially radially movable plungers mounted insaid casing, traction plates on said plungers, friction devicesangularly movable about the axes of said plungers to engage said tire,means to normally hold said friction devices in inoperative position,and manual means to release said devices.

19. A traction increasing device for an automobile having a wheel andtire comprising a support loosely mounted for rotation concentric withthe wheel axis, a plurality of spaced outwardly extending membersmounted to move toward and from the tire and relative to said support ina direction substantially perpendicular to the wheel axis and havingtraction plates at their outer ends overlying said tire at all times,means to hold said support and members from rotation with said wheel,and'means to cause said members to rotate with said wheel.

20. A traction increasing device for an automobile as set forth in claim19, in which the means for causing the members to rotate with the wheelis manually controlled but the movement of said traction plates towardthe tire tread is automatically eiTected by engagement of any one ofsaid plates with the surface on which said wheel and tire roll.

RALPH HODGKINSON.

